createIndex

The createIndex Change Type creates an index on an existing column or a set of columns.

Uses

You can typically use the createIndex Change Type when you want to add an index on one of the columns or a set of columns to increase the searchability of the records in your database.

If you set the clustered attribute to true, Liquibase will create a clustered index, which defines the order in which records are stored in a table. If you set the clustered attribute to false, Liquibase will create a non-clustered index, where the order of the rows will not match the order of the actual records.

When creating indexes, Liquibase uses the order of columns that you list in the createIndex Change Type. For example:

<changeSet author="bob" id="1_createTable_department"> <createTable tableName="department"> <column name="col_1" type="integer"/> <column name="col_2" type="integer"/> <column name="col_3" type="integer"/> </createTable> </changeSet> <changeSet author="bob" id="1_createIndex_index_one"> <createIndex indexName="index_one" tableName="department"> <column name="col_1"/> <column name="col_2"/> <column name="col_3"/> </createIndex> </changeSet> <changeSet author="bob" id="2_createIndex_index_two"> <createIndex indexName="index_two" tableName="department"> <column name="col_3"/> <column name="col_2"/> <column name="col_1"/> </createIndex> </changeSet> <changeSet author="bob" id="3_createIndex_index_three"> <createIndex indexName="index_three" tableName="department"> <column name="col_2"/> <column name="col_3"/> <column name="col_1"/> </createIndex> </changeSet>

These changesets will produce the following (the update-sql command example):

CREATE TABLE public.department (col_1 INT, col_2 INT, col_3 INT); CREATE INDEX index_one ON public.department(col_1, col_2, col_3); CREATE INDEX index_two ON public.department(col_3, col_2, col_1); CREATE INDEX index_three ON public.department(col_2, col_3, col_1);

Running the createIndex Change Type

To run this Change Type, follow these steps:

  1. Add the Change Type to your changeset, as shown in the examples on this page.

  2. Specify any required attributes. Use the table on this page to see which ones your database requires.

  3. Deploy your changeset by running the update command: liquibase update

Available attributes

Name

Description

Required for

Supports

associatedWith

Specifies which columns to filter in the index you're creating. Some databases, like Oracle, automatically create indexes for primary key constraints and unique constraints, but not foreign key constraints. Use this attribute to specify what your index associations are. Valid values: primaryKey, foreignKey, uniqueConstraint, none.

catalogName

Name of the catalog

all

clustered

Boolean. Whether to create a clustered index

all

indexName

Name of the index

firebird, hsqldb

all

schemaName

Name of the schema

all

tableName

Name of the table for which to add the index.

all

all

tablespace

Name of the tablespace to use for the index

all

unique

Defines whether a unique clause should be applied

all

using

Only available for PostgreSQL. Defines what index type is used. Valid values: btree, gin, hash, gist, spgist, brin. All available index types and their uses are documented by PostgreSQL.

PostgreSQL

Nested tags

Name

Description

Required for

Supports

Multiple allowed

column

The column(s) to add to the index.

Note: YAML and JSON changelogs using the column tag must nest it within a columns tag.

all

all

yes

Nested property attributes

Name

Description

Required for

Supports

name

Name of the column. It can contain the direction by appending

ASC

or

DESC

to the name.

all

all

computed

Set to

true

if the value in

name

isn't actually a column name but a function. Boolean.

Since 3.3.0.

descending

Specifies that a column should be used in a descending order in the index. (i.e. ascending order)

--

Since 3.4.

Database support

Database

Notes

Auto Rollback

DB2/LUW

Supported

Yes

DB2/z

Supported

Yes

Derby

Supported

Yes

Firebird

Supported

Yes

Google BigQuery

Supported

Yes

H2

Supported

Yes

HyperSQL

Supported

Yes

INGRES

Supported

Yes

Informix

Supported

Yes

MariaDB

Supported

Yes

MySQL

Supported

Yes

Oracle

Supported

Yes

PostgreSQL

Supported

Yes

Snowflake

Not Supported

No

SQL Server

Supported

Yes

SQLite

Supported

Yes

Sybase

Supported

Yes

Sybase Anywhere

Supported

Yes

createIndex examples 

--liquibase formatted sql
--changeset liquibase-docs:createIndex-example
CREATE UNIQUE INDEX idx_address ON department.person (address DESC);

Changing the index type for PostgreSQL

PostgreSQL provides several index types. Each index type uses a different algorithm. You can choose the one that best fits your project’s performance needs. The PostgreSQL documentation provides all available index types and their use cases.

You can use the following example code to set the index type for your project. You'll need to set the using attribute to the index type you want to use. These examples use gin.

Index type for PostgreSQL examples 

--liquibase formatted sql
--changeset liquibase-docs:createIndex-example
CREATE UNIQUE INDEX idx_address ON department.person (address DESC) USING GIN ("test");